The present invention pertains to a folding device for carton bottoms. More particularly, the present invention pertains to an apparatus for in-folding, for sealing, over-folded carton bottoms.
A common form of container for milk, juice and the like is the gable top carton. In this regard, packaging technology has made enormous strides vis-à-vis these gable top cartons, as well as other types of packages. Present technology permits the packaging of perishable food items for non-refrigerated shelf lives that can be as much as 90 days. Such packages provide the ability to bring these food items into parts of the world that have limited transportation, distribution and storage infrastructure.
To this end, efforts have been directed to increasing the ability to maintain high levels of cleanliness in forming, filling and sealing these containers to provide the highest quality product and to provide the greatest product shelf life. And, in conjunction with this, the demands on packaging machines have become greater, in particular, relative to operating speeds. One packaging machine in which cartons or packages are formed, filled and sealed in a sterile environment by a single machine an operate at machine speeds that exceed 10,000 packages per hour.
In order to maintain the integrity of the package after it is filled and sealed, advanced technologies have been applied to the carton materials, as well as the processing operations. Many such packaging materials are formed from paperboard or fiberboard-based materials formed in a composite structure. Typically, one or more layers, such as polymeric coatings, foil coatings and the like, are applied to the paperboard or fiberboard substrate to reduce or eliminate the gas and liquid permeability of the substrate material.
In the form, fill and seal process, it has been observed that the contact of machine parts with the carton material tends to result in the generation of dust. This is particularly so when machine parts contact container material surfaces at relatively high rates of speed (e.g., when machine parts continuously contact container material surfaces relatively soon after the heating process, especially at the bottom forming and sealing process, in that the packaging material surface is easily scratched when the polymer surface is soft). For example, when machine parts (moving at a relative speed that is greater than the speed of the moving container) contact the container. One particular area in which this is observed is the bottom panel folding assembly.
Known bottom panel folding assemblies include a pair of spaced apart rotating hubs having multiple outwardly extending fingers. As the carton passes between the hubs, the fingers contact the flaps and fold over the flaps. Although this assembly works quite well to fold the flaps and to provide a well folded and sealed arrangement, it tends to generate a considerable amount of dust.
Accordingly, there exists a need for a carton bottom folding device for folding over-folded carton bottoms, which device can be used with known form, fill and seal machines. Desirably, such a folding device can accommodate carton folding operations at the operating speeds of known filling machines. Most desirably, the folding device carries out the folding operation while reducing the amount of dust generated.